1vsm
From Proteopedia
(New page: 200px<br /><applet load="1vsm" size="450" color="white" frame="true" align="right" spinBox="true" caption="1vsm, resolution 2.15Å" /> '''ASV INTEGRASE CORE D...) |
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| - | [[Image:1vsm.gif|left|200px]]<br /><applet load="1vsm" size=" | + | [[Image:1vsm.gif|left|200px]]<br /><applet load="1vsm" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1vsm, resolution 2.15Å" /> | caption="1vsm, resolution 2.15Å" /> | ||
'''ASV INTEGRASE CORE DOMAIN IN CITRATE BUFFER PH 5.0'''<br /> | '''ASV INTEGRASE CORE DOMAIN IN CITRATE BUFFER PH 5.0'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Crystallographic studies of the catalytic core domain of avian sarcoma | + | Crystallographic studies of the catalytic core domain of avian sarcoma virus integrase (ASV IN) have provided the most detailed picture so far of the active site of this enzyme, which belongs to an important class of targets for designing drugs against AIDS. Recently, crystals of an inactive D64N mutant were obtained under conditions identical to those used for the native enzyme. Data were collected at different pH values and in the presence of divalent cations. Data were also collected at low pH for the crystals of the native ASV IN core domain. In the structures of native ASV IN at pH 6.0 and below, as well as in all structures of the D64N mutants, the side chain of the active site residue Asx-64 (Asx denotes Asn or Asp) is rotated by approximately 150 degrees around the Calpha---Cbeta bond, compared with the structures at higher pH. In the new structures, this residue makes hydrogen bonds with the amide group of Asn-160, and thus, the usual metal-binding site, consisting of Asp-64, Asp-121, and Glu-157, is disrupted. Surprisingly, however, a single Zn2+ can still bind to Asp-121 in the mutant, without restoration of the activity of the enzyme. These structures have elucidated an unexpected mechanism of inactivation of the enzyme by lowering the pH or by mutation, in which a protonated side chain of Asx-64 changes its orientation and interaction partner. |
==About this Structure== | ==About this Structure== | ||
| - | 1VSM is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Rous_sarcoma_virus Rous sarcoma virus]. Active as [http://en.wikipedia.org/wiki/RNA-directed_DNA_polymerase RNA-directed DNA polymerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.7.49 2.7.7.49] Full crystallographic information is available from [http:// | + | 1VSM is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Rous_sarcoma_virus Rous sarcoma virus]. Active as [http://en.wikipedia.org/wiki/RNA-directed_DNA_polymerase RNA-directed DNA polymerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.7.49 2.7.7.49] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1VSM OCA]. |
==Reference== | ==Reference== | ||
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[[Category: transferase]] | [[Category: transferase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:38:11 2008'' |
Revision as of 13:38, 21 February 2008
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ASV INTEGRASE CORE DOMAIN IN CITRATE BUFFER PH 5.0
Overview
Crystallographic studies of the catalytic core domain of avian sarcoma virus integrase (ASV IN) have provided the most detailed picture so far of the active site of this enzyme, which belongs to an important class of targets for designing drugs against AIDS. Recently, crystals of an inactive D64N mutant were obtained under conditions identical to those used for the native enzyme. Data were collected at different pH values and in the presence of divalent cations. Data were also collected at low pH for the crystals of the native ASV IN core domain. In the structures of native ASV IN at pH 6.0 and below, as well as in all structures of the D64N mutants, the side chain of the active site residue Asx-64 (Asx denotes Asn or Asp) is rotated by approximately 150 degrees around the Calpha---Cbeta bond, compared with the structures at higher pH. In the new structures, this residue makes hydrogen bonds with the amide group of Asn-160, and thus, the usual metal-binding site, consisting of Asp-64, Asp-121, and Glu-157, is disrupted. Surprisingly, however, a single Zn2+ can still bind to Asp-121 in the mutant, without restoration of the activity of the enzyme. These structures have elucidated an unexpected mechanism of inactivation of the enzyme by lowering the pH or by mutation, in which a protonated side chain of Asx-64 changes its orientation and interaction partner.
About this Structure
1VSM is a Single protein structure of sequence from Rous sarcoma virus. Active as RNA-directed DNA polymerase, with EC number 2.7.7.49 Full crystallographic information is available from OCA.
Reference
Structural basis for inactivating mutations and pH-dependent activity of avian sarcoma virus integrase., Lubkowski J, Yang F, Alexandratos J, Merkel G, Katz RA, Gravuer K, Skalka AM, Wlodawer A, J Biol Chem. 1998 Dec 4;273(49):32685-9. PMID:9830010
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